<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script src="js/jquery.js"></script>
<script>
    var arr=[2,4,7]
    $.each(arr,function (index,item) {
        console.log(index,item)
    })

    var str='  sad sd   '
    console.log(str.trim())
</script>
</body>
</html>
